The goal of the proposed research is to purify and characterize all antigens which are secreted by the infective L1 larva of Trichinella spiralis. Purifications will be accomplished employing antigen-enriched fractions of infective L1 larvae by immuno-affinity chromatography and monoclonal antibodies. Each purified antigen will be assayed for its ability to induce protection against an oral challenge infection in mice. Protection-inducing antigens will be characterized physically (molecular weight), chemically (total carbohydrate content, amino sugars, amino acid composition, tryptic digest fingerprint), and biologically (localization within the infective L1 larva, fate in host tissues during the enteral phase of infection in the normal and immunized host). All purified antigens will be used in the micro-ELISA test in order to assess their usefulness in the serodiagnosis of swine and human trichinellosis.